Share This Article:

Control of an Industrial SCR Catalyst Using Ceramic NOx Sensors

Abstract Full-Text HTML Download Download as PDF (Size:712KB) PP. 317-324
DOI: 10.4236/epe.2011.33039    7,061 Downloads   11,323 Views   Citations

ABSTRACT

Selective Catalytic Reduction (SCR) catalysts respond slowly to transient inputs, which is troublesome when designing ammonia feed controllers. An experimental SCR test apparatus installed on a slipstream of a Coo-per-Bessemer GMV-4, 2-stroke cycle natural gas engine is utilized. Ammonia (NH3) feed rate control algo-rithm development is carried out. Two control algorithms are evaluated: a feed forward control algorithm, using a pre ammonia injection ceramic NOx sensor and a feed forward plus feedback control algorithm, us-ing a pre ammonia injection ceramic NOx sensor and post catalyst ceramic NOx sensor to generate feedback signals. The feed forward algorithm controls to constant user input NH3/NOx molar ratio. The data show the lack of pressure compensation on the ceramic NOx sensors cause errors in feed forward NOx readings, re-sulting in sub optimal ammonia feed. The feedback system minimizes the post catalyst ceramic NOx sensor signal by adjusting the NH3/NOx molar ratio. The NOx sensors respond to ammonia + NOx; therefore, the feed forward plus feedback algorithm minimizes the sum of NOx emissions and ammonia slip. Successful application of the feedback control minimization technique is demonstrated with feedback periods of 15 and 5 minutes with molar ratio step sizes of 5 and 2.5%, respectively.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

J. Schmitt and D. Olsen, "Control of an Industrial SCR Catalyst Using Ceramic NOx Sensors," Energy and Power Engineering, Vol. 3 No. 3, 2011, pp. 317-324. doi: 10.4236/epe.2011.33039.

References

[1] M. Chen and S. Williams, “Modeling and Optimization of SCR-Exhaust Aftertreatment Systems,” SAE International, 2005, Article No. 2005-01-0969.
[2] C. M. Sch?r, C. H. Onder and H. P. Geering, “Control of an SCR Catalytic Converter System for a Mobile Heavy-Duty Application,” IEEE Transactions on Control Systems Technology, Vol. 14, No. 4, 2006, pp. 641-653. doi:10.1109/TCST.2006.876634
[3] C. M. Sch?r, “Control of a selective catalytic reduction process. IMRT Press c/o Institut für Mess- und Regeltechnik, ETH Zentrum, 2003.
[4] D. Simpson, “Precombustion Chamber Design for Emissions Reduction from Industrial Natural Gas Engines,” Master’s Thesis, Colorado State University, Fort Collins, 2009.
[5] J. Lisowski, “Diagnostic Techniques for Precombustion Chambers in Large Bore Lean Burn Natural Gas Engines,” Master’s Thesis, Colorado State University, Fort Collins, 2007.
[6] K. Ivaturi, “Experimental and CFD Investigation of Re-agent Mixing in an SCR System,” Master’s Thesis, Colorado State University, Fort Collins, 2007.
[7] T. Moosman, “FTIR Spectroscopy for 2-Stroke, Lean Burn Gas Engines Emphasizing Low-Level Detection of HAPs,” Master’s Thesis, Colorado State University, Fort Collins, 2005.

  
comments powered by Disqus

Copyright © 2019 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.